LIBRARY 
STATE  PLANT  BOARCJ 


Circular  No.  27,  Second  Series. 


United  States  Department  of  Agriculture, 

DIVISION  OF  ENTOMOLOGY. 


THE  MEXICAN  COTTON-BOLL  WEEVIL  IN  1807. 

PREVIOUS   PUBLICATIONS. 

Soon  after  the  Mexican  cotton-boll  weevil  {Anthonomus  grandis) 
made  its  appearance  in  Texas  cotton-fields  a  circular  (No.  G,  n.  s.) 
was  prepared  by  the  writer  and  distributed  during  April,  1895,  to 
cotton  planters  living  in  the  infested  regions.  The  results  of  the 
work  during  1895  were  published  in  Circular  No.  14,  of  this  series, 
and  distributed  to  Texas  cotton  planters  in  February,  1896.  An 
edition  of  the  same  circular  in  Spanish  was  published  during  the 
same  month.  The  results  obtained  by  the  work  of  189G  were  given 
in  the  circular  (18  of  this  series)  published  in  February,  1897.  This 
Circular  No.  18  gives  in  complete  form  the  life  history  of  the  insect, 
its  habits,  and  the  remedy  to  be  used  against  it.  It  also  contains 
information  regarding  its  distribution  in  Texas  at  the  close  of  the 
season  of  1896.  Editions  of  this  circular  in  the  Spanish  and  German 
languages  were  published  during  the  same  month  for  distribution  to 
Mexicans  and  Germans  living  in  south  Texas,  who  are  more  familiar 
with  their  native  language  than  with  English. 

SCOPE    OF   PRESENT    CIRCULAR. 

The  ground  of  the  natural  history  of  the  insect  and  the  remedies 
having  been  so  fully  discussed  in  Circular  No.  18,  the  edition  of 
which  is  as  yet  by  no  means  exhausted,  it  will  be  necessary  at  this 
time  simply  to  give  the  facts  concerning  the  work  of  the  insect  dur- 
ing the  summer  of  1897. 

THE    OBSERVATIONS    OF    THE    SEASON   OF    1897. 

As  injurious  as  this  insect  has  been,  especially  during  the  summer 
and  autumn  of  1895,  and  less  so  in  the  two  succeeding  years,  to  the 
planters  whose  fields  it  has  actually  entered,  a  greater  cause  for 
alarm  existed  through  the  probability  of  its  spread  into  more  impor- 
tant cotton-growing  regions.  Thus  the  reports  of  damage  in  1895 
greatly  disturbed  the  cotton  planters  not  only  of  the  rich  country 
lying  to  the  north  and  east  of  the  infested  region  in  the  State  of 
Texas,  but  also  the  planters  of  Louisiana,  Mississippi,  Alabama,  and 
Georgia.  It  was  at  first  thought  that  the  spread  of  the  insect  into 
these  regions  would  be  certain  and  rapid.  The  investigations  of  the 
first  season  largely  negatived  this  possibility,  and  now,  after  three 
seasons'  observations,  it  appears  that  the  spread  of  the  insect  toward 


ft 


the  north  and  east  has  been  very  slow ;  that  this  spread  is  practically 
checked  by  the  first  heavy  frost,  and  that  it  is  doubtful  whether  it 
^vill  spread  to  any  great  extent  beyond  the  region  of  growth  of 
volunteer  cotton. 

In  the  early  part  of  the  season  an  agent  of  this  office,  Mr.  C.  H.  T. 
Townsend,  was  commissioned  to  investigate  wild  and  cultivated  cot- 
ton in  south  Mexico,  which  was  assumed  to  be  the  original  home  of 
the  insect,  although  the  greatest  reports  of  damage  in  Mexico  have 
come  from  more  northern  counties.  Mr.  Townsend  was  stationed 
during  the  spring  and  early  summer  months  in  the  State  of  Tabasco, 
and  had  no  difficulty  in  finding  the  weevil  breeding  very  extensively 
as  early  as  February  in  the  squares  of  wild  cotton  and  in  following 
it  on  until  July  in  the  bolls.  He  reared  many  specimens  of  the 
weevil,  but  was  unsuccessful  in  finding  any  parasites.  He  had  been 
sent  down  there  to  see  whether  native  parasites  could  be  found  which 
might  be  introduced  to  advantage  into  Texas  cotton  fields.  He  sent, 
during  this  time,  from  Tabasco  to  this  office  in  Washington,  numerous 
specimens  of  bolls  containing  this  insect  in  different  stages ;  and  the 
writer  has  also  been  unsuccessful  in  rearing  any  parasites,  although 
dried  fragments  in  some  of  the  bolls  indicate  that  such  a  parasite 
does  exist;  probably,  however,  in  insignificant  numbers.  The  very 
fact  of  the  occurrence  of  the  weevil  in  such  quantity  in  Tabasco  is 
in  itself  an  indication  that  no  effective  parasite  is  to  be  found  there. 

In  October  and  early  November  Mr.  Townsend  was  sent  through 
the  infested  region  in  Texas  for  the  purpose  of  examining  the  con- 
ditions and  learning  whether  the  insect  had  spread.  Such  an  inves- 
tigation was  not  necessary  in  the  early  season  of  the  year  for  the 
reason  that  previous  experience  has  shown  us  that  the  spread  of  the 
insect  takes  place  in  the  autumn  if  at  all.  The  early  generations  in 
the  more  northern  portions  of  the  range  of  the  species  are  not  so 
numerous  as  the  later  ones  and  the  migratory  instinct  does  not  become 
developed  as  long  as  there  is  plenty  of  food.  Wherever  in  a  weevil- 
infested  field  the  reasonably  complete  loss  of  the  top  crop  through 
drought  or  from  some  other  cause  brings  about  a  lack  of  food  for  the 
weevils  in  October  or  later,  they  then  migrate  in  search  of  food  and 
proper  places  to  lay  their  eggs. 

The  statements  which  follow  have  been  derived  largely  from  Mr. 
Townsend's  reports. 

CONDITIONS    AND    SPREAD    DURING   1897. 

In  all  the  infested  region  the  crop  this  year  seems  to  have  been  very 
short,  ranging  from  1  bale  to  6  acres  to  1  bale  to  10  or  even  15  acres 
on  uplands.  This  condition  is  largely  attributed  to  drought.  In  the 
bottom  lands  at  Victoria  the  yield  was  from  one-quarter  to  one-half 
bale  per  acre,  and  had  it  not  been  for  the  weevil  a  good  top  crop 
would  have  been  realized.  On  the  uplands  almost  no  top  crop  was 
made,  although  there  was  a  slight  yield  here  and  there  in  occasional 
fields,  as  at  San  Antonio,  Gonzales,  and  Goliad.  At  Kenedy  Mr. 
Townsend  found  that  the  yield  averaged  1  bale  to  10  acres ;  at  Cuero, 
1  bale  to  8  acres ;  at  Victoria,  1  bale  to  from  2  to  25  acres,  varying 
from  bottom  lands  to  uplands ;  at  Goliad,  1  bale  to  G  acres ;  at  Bee- 
ville,  1  bale  to  8  acres.  This  will  show  about  the  yield  of  the  central 
portion  of  the  area  heretofore  known  to  be  infested  by  the  weevil. 


Where  it  was  found  that  there  was  n(3  top  crop  th(;r(3  wore  viivy 
few  weevils  present  in  the  fields.  There  were  almost  no  s(iu;ires  and 
but  few  bolls.  In  the  lowlands,  however,  and  where  tho  {slants 
showed  some  growth  of  squares,  the  weevil  and  its  work  were  abund- 
ant. Careful  investigation  of  the  country  adjoining  the  bord(;rs  of 
the  infested  area  of  189G  showed  only  one  important  ext(;nsion  of 
spread,  this  being  immediately  to  the  north  of  Cuero.  Here  the 
weevil  has  extended  as  far  to  the  north  as  Harwood,  Thompsonville, 
and  Moravia,  entering  the  country  around  Yoakum  and  Gonzales 
and  extending  probably  to  within  5  or  10  miles  of  Halle ttsville  and 
Luling.  It  was  especially  noticed  that  in  these  outlying  areas  of 
spread  the  weevil  is  more  or  less  confined  to  the  valleys  of  streams 
or  the  low-lying  lands,  and  that  the  adult  weevils  are  frequently  very 
numerous,  with  few  or  no  larvae,  indicating  that  the  weevils  had 
arrived  very  recently.  However,  near  Thompsonville,  which  is  about 
9  miles  east  of  Harwood  and  the  most  northerly  point  at  which  the 
weevil  has  been  found,  a  one-fourth  grown  larva  was  discovered  in 
a  square  on  November  6.  Between  Thompsonville  and  Harwood 
some  few  squares  in  the  fields  show  their  work,  but  adult  weevils  are 
not  often  to  be  found,  except  near  Harwood  where  they  were  more 
plentiful. 

At  Victoria,  in  the  bottom  lands  where  the  cotton  was  not  hurt  by 
drought  and  was  full  of  squares,  the  weevils  were  very  numerous. 
The  following  is  a  table  of  the  localities  examined  by  Mr.  Townsend, 
showing  those  in  which  the  weevil  was  present  and  those  in  which  it 
was  absent : 


Present. 
San  Antonio  (very  scarce). 
Kenedy  (scarce  from  lack  of  food). 
Cuero  (not  abundant). 
Victoria    (abundant    with    plenty    of 

food). 
Beeville  (not  abundant). 
Yoakum   (numerous  where  there  are 

squares). 
Gonzales  (numerous). 
Moravia    (numerous    near    live    oak 

stretches). 
Harwood  (numerous  where  there  are 

squares) . 
Shiner    (numerous    where    there    are 

squares). 
Thompsonville  (scarce). 
Port  Lavaca   (reported  sparingly  but 

not  visited) . 

At  Columbus,  Wharton,  East  Bernard,  and  Hungerford  there  was 
as  a  rule  a  good  top  crop,  this  being  in  or  bordering  the  Colorado 
bottom  lands,  while  at  San  Antonio,  Luling,  and  Gonzales  there  was 
only  a  partial  crop.  The  territory  to  the  south  of  Beeville  was  not 
explored  by  Mr.  Townsend  on  account  of  its  lack  of  significance  as 
affecting  conditions  of  possible  spread.  Judge  S.  G.  Borden,  of 
Sharpsburg,  however,  informs  us,  under  date  of  December  28,  that 
the  weevil  did  very  considerable  damage  in  San  Patricio  and  Nueces 
counties  during  the  season.  He  estimates  that  about  one-half  the 
crop  was  destroyed  by  weevil.  He  thinks,  however,  that  they  were 
not  as  numerous  as  in  either  1895  or  189G. 


Absent . 

Hallettsville  (probably  approach  within 
5  or  10  miles  to  west). 

Luling  (probably  extend  to  within  5 
miles  to  south  along  river). 

Seguin. 

Marion. 

Converse. 

Lacoste. 

Pearsall. 

Moore. 

Wharton  (probably  approach  no  far- 
ther than  Edna) . 

Hungerford. 

East  Bernard. 

Columbus. 

Sclmlenberg. 

Flatonia. 


PROSPECTS   FOR   NEXT    SEASON. 

At  the  close  of  1895  it  was  feared  that  there  would  be  a  consider- 
able spread  during  189G.  The  severe  midsummer  drought  in  189G, 
however,  resulted  in  not  only  limiting  this  spread  but  in  bringing 
about  a  shrinkage  of  the  territor}"  infested.  Probably  another  factor 
which  assisted  in  this  shrinkage  was  the  severe  frost  of  the  first  week 
of  December,  1890,  which  certainly  resulted  in  the  destruction  of  the 
majority  of  the  insects  at  San  Antonio,  and  probably  also  at  Whar- 
ton, where  the  weevil  was  abundant  in  a  certain  field  and  where  it 
has  not  since  been  found.  At  San  Antonio,  by  the  way,  in  a  field 
which  was  very  badly  infested  in  November,  1895,  no  specimens  of 
the  insect  were  found  during  189G  and  but  a  single  adult  weevil  was 
captured  in  October,  1897.  The  slight  spread  to  the  north  and  east 
during  1897  renders  it  difficult  to  premise  as  to  1898.  The  almost 
uniform  absence  of  a  top  crop  over  regions  where  the  insect  has 
previously  been  abundant,  resulting  in  a  great  scarcity  during  Octo- 
ber, will  probably  make  the  insect  scarce  in  numbers  in  the  fields 
next  spring.  The  writer  would  not  be  inclined  to  expect  any  great 
damage  in  such  localities  in  the  early  part  of  1898. 

Mr.  Townsend  writes :  "I  consider  that  the  weevil  has  been  set 
back  greatly  over  nearly  the  whole  of  the  infested  district  this  year." 
The  spread  which  did  occur,  however,  although  not  a  great  one,  is 
serious  from  its  direction.  With  heavy  frosts  in  the  early  winter  the 
prospects  for  the  further  spread  of  the  insect  in  the  same  general 
direction  next  summer  will  be  very  slight.  Without  such  frosts  it  is 
to  be  feared  that  toward  the  end  of  the  summer  of  1898  there  uislj 
be  a  further  spread  toward  the  Colorado  River. 

In  general  terms  it  may  be  said  that  the  damage  done  by  the  weevil 
bears  a  direct  proportion  to  the  value  of  the  top  crop,  and  since  in 
southern  Texas  the  top  crop  is  probably  proportionately  more  valu- 
able than  in  other  portions  of  the  cotton  belt,  owing  to  the  greater 
length  of  the  season,  it  is  here  that  the  damage  from  the  weevil  must 
always  be  greatest. 

THE   WEEVIL   IN   GINNED  SEED  AND   SEED   COTTON. 

It  was  the  writer's  first  supposition  that  the  insect  was  brought 
from  the  comparatively  isolated  region  about  Matamoras,  Mexico, 
and  Brownsville,  Texas,  to  Alice  or  San  Diego  or  Corpus  Christi  in 
unginned  cotton.  Later  observations  seemed  to  negative  this  suppo- 
sition, since  the  insect  was  not  found  about  the  gins.  Mr.  Town- 
send,  however,  the  present  fall,  in  visiting  a  gin  at  Victoria,  found 
numbers  of  lively  adult  weevils  crawling  about  not  only  in  the 
unginned  seed  cotton  but  even  in  the  ginned  cotton  after  it  had 
passed  through  the  machine.  Man}^  gins  had  been  examined  before 
this  in  both  Texas  and  Mexico,  but  such  facts  had  never  before  been 
observed.  This  indicates  the  possibility  that  the  weevil  may  be 
taken  from  place  to  place  in  ginned  seed  as  well  as  in  ginned  cotton. 

ANOTHER   WEEVIL   MISTAKEN    FOR   THE    COTTON   BOLL   WEEVIL. 

In  the  first  two  circulars  published  about  this  insect  the  writer 
referred  to  several  insects  which  were  mistaken  for  the  true  cotton 
boll  weevil  and  figured  one  of  them,  viz.,  the  form  known  as  the 


"sharp-shooter,"  a  leaf-hopj)er  scientifically  known  as  Ifomalodisca 
coagulata.  The  figure  was  omitted  from  the  last  two  circulars 
since  it  was  found  that  illiterate  persons  looking  at  the  circular 
believed  that  the  figure  represented  the  true  weevil.  Moreover,  a 
growing  and  more  definite  acquaintance  with  the  true  weevil  rend- 
ered mistakes  much  less  frec^uent.  The  present  year,  Innvever,  there 
has  been  an  extraordinary  abundance  of  an  acorn  weevil  which  has 
flown  to  the  lights  in  Victoria,  Cuero,  Beeville,  Goliad,  and  many 
other  towns  to  the  north.  These  occurrences  began  in  September 
with  the  first  "norther,"  the  weevils  swarming  in  the  open  houses 
at  light  in  the  evening.  They  w^ere  universally  thought  to  be  the 
cotton  weevil  and  created  much  alarm.  Specimens  were  sent  by  a 
number  of  different  corresj^ondents  to  this  office,  among  them  a  very 
great  number  which  were  collected  by  the  Hon.  J.  D.  Mitchell,  at 
Victoria,  in  some  experiments  which  he  was  making  with  a  trap- 
lantern  during  that  month.  Mr.  Townsend  was  aole  to  allay  the 
alarm  to  a  considerable  extent.  The  mistake  was  by  no  means  a 
bad  one,  since  the  acorn  weevil  bears  a  strong  superficial  resemblance 
to  the  Mexican  cotton  boll  wee^^l.  It  is  a  somewhat  larger  insect, 
however,  and  has  a  longer  and  thinner  beak. 

MACHINES    FOR   THE    DESTRUCTION    OF   THE    INSECT. 

In  Circular  18  we  mentioned  a  machine  invented  by  Mr.  Stronhall, 
of  Beeville,  and  which  was  intended  to  jar  the  affected  squares  and 
blossoms  from  young  cotton  plants  and  to  collect  them  at  the  same 
time.  Mr.  Stronhall  has  been  working  upon  this  machine  during  the 
summer,  and  is  now  endeavoring  to  perfect  it  so  as  to  crush  the  wee- 
vil between  rollers  when  collected.  He  is  also  endeavoring  to  render 
it  less  expensive  in  price.  Mr.  Townsend  was  told  that  this  gentle- 
man himself  used  his  old  machine  on  his  plantations  12  miles  south 
of  Beeville  and  secured  one-half  bale  to  the  acre,  also  getting  some 
top  crop. 

Another  machine,  for  the  distribution  of  dry  poison,  has  been  pat- 
ented by  Mr.  Richter,  of  Moravia.  This  machine,  which  Mr.  Town- 
send  saw  in  operation,  and  of  which  he  has  sent  the  writer  photo- 
graphs, is  well  adapted  to  its  purpose,  and  Mr.  Townsend  writes  is 
very  successful  as  a  distributor  of  dry  dust.  Whether  it  can  be  used 
to  advantage  against  the  weevil  is  yet  a  question  in  our  minds,  but 
it  will  be  an  excellent  machine  to  use  against  the  cotton  caterpillar. 
The  machine  is  drawn  by  a  pair  of  horses,  straddling  a  row  and  dust- 
ing three  to  five  rows  of  cotton  at  once.  The  horses  must  be  driven 
at  a  smart  trot  so  as  to  blow  the  poison  out  rapidly.  Ten  acres  can 
be  dusted  in  an  hour  with  poison  for  the  cotton  w^orm. 

THE  VALUE   OF  DOMESTIC  FOWLS  AS  DESTROYERS  OF  THE  WEEVIL. 

We  are  indebted  to  Mr.  F.  M.  Howard,  county  clerk  of  Bee  County, 
living  at  Beeville,  for  an  interesting  account  of  the  incidental  value 
of  keeping  turkeys.  He  w^rites  that  he  found  one  farmer  who  during 
last  winter  had  put  100  turkeys  on  his  farm,  had  planted  To  acres, 
and  made  2G  bales,  and  was  not  troubled  with  the  w^eevil  during  the 


6 

season,  while  a  neighbor,  who  had  no  poultry,  planted  450  acres  and 
gathered  less  than  50  bales,  the  land  being  exactly  of  the  same  class 
of  soil.  Mr.  Howard  also  states  that  all  the  quail  killed  near  Beeville 
have  their  crops  filled  with  the  weevil. 

REMEDIES. 

We  have  nothing  to  add  to  the  remarks  published  in  Circular  18 
on  the  subject  of  remedies.  In  the  cultural  method  of  control  (there 
mentioned  in  detail)  we  believe  that  a  practically  complete  remedy 
for  the  insect  will  be  found.  We  may  briefly  reiterate  the  recom- 
mendations regarding  this  method : 

' '  The  careful  investigation  of  this  weevil  during  the  past  two  or 
three  years  by  the  Division  of  Entomology  has  fully  demonstrated 
the  supreme  importance  of  the  cultural  method  of  control,  to  which 
fact  we  gave  special  prominence  in  our  first  circular  on  this  insect. 
There  can  be  no  question  now  that  in  the  proper  system  of  growing 
cotton  a  practically  complete  remedy  for  the  weevil  exists.  In  the 
first  place,  it  has  been  established  beyond  question  that  the  conditions 
of  cultivation  which  make  volunteer  growth  possible  also  make  the 
continuance  of  the  weevil  inevitable.  Of  first  importance  is  the 
early  removal  of  the  old  cotton  in  the  fall,  preferably  in  November 
or  earlier.  This  can  be  done  by  throwing  out  the  old  plants  with  a 
plow,  root  and  all,  and  afterwards  raking  them  together  and  burning 
them.  This  treatment  should  be  followed,  as  promptly  as  may  be, 
by  deep  plowing,  say  to  a  depth  of  6  or  8  inches.  This  leaves  the 
field  comparatively  clean  of  old  cotton  stalks,  facilitates  thorough 
cultivation  the  following  year,  and,  at  the  same  time,  collects  and 
destroys  all  of  the  weevil  larvae  and  pupse  in  the  cotton  at  the  time, 
and  also  most  of  the  adults.  The  escaping  beetles  will  be  buried  by 
deep  plowing,  and  will  not  again  reach  the  surface.  Few,  if  any, 
of  them  will  succeed  in  hibernating  in  the  absence  of  the  ordinary 
rubbish  in  the  fields  in  which  they  winter.  Fields  treated  in  this 
way  have  given  a  practical  demonstration  of  the  usefulness  of  this 
method. 

' '  The  greatest  danger  from  the  weevil  is  due  to  the  presence  of 
volunteer  cotton,  which  means  early  food  for  the  weevils  in  the 
spring  and  abundant  means  for  their  overwintering,  and  the  effort 
made  to  retain  volunteer  and  get  early  cotton,  or  the  '  first  bale, '  is  a 
very  serious  menace  to  cotton  culture  within  the  weevil  district. 

"This  cultural  method,  if  generally  practiced,  will  undoubtedly 
prove  a  perfect  remedy  for  upland  cotton,  and  will  vastly  reduce 
weevil  damage  in  the  lowland,  where  the  weevil  is  more  apt  to 
winter,  perhaps  in  adjoining  woods  or  roadside  vegetation.  The 
early  removal  of  cotton  by  the  means  suggested  is  especially  advised 
whenever  the  presence  of  the  weevil  shows  that  the  picking  of  a  top 
crop  is  problematical.  In  such  instances  it  would  be  well  to  uproot 
and  destroy  cotton  stalks  in  September  or  October.  If  this  cultural 
method  can  be  enforced,  either  by  State  legislation  or  by  the  cooper- 
ation and  insistence  on  the  part  of  landowners  that  their  renters  shall 
carry  out  the  system  outlined,  the  weevil  difficulty  can  undoubtedly 
in  very  large  measure  be  overcome. 


"In  connection  with  the  S3^stem  of  full  trcatnic^nt  of  tho  cotton, 
constant  and  thorough  cultivation  of  the  growing  croj)  as  late  as  pos- 
sible is  of  considerable  value,  and  is  also  what  should  be  done  to  insure 
a  good  yield.  With  a  crossbar  to  brush  the  plants  many  of  the  blos- 
soms and  squares  containing  weevils  will  be  jarred  to  the  ground 
and  buried,  together  with  those  already  on  the  ground,  in  nnjist  soil, 
and  a  large  percentage  of  the  material  will  rot  before  contained  in- 
sects have  developed." 

L.  O.  Howard, 

Approved :  Entomologist. 

James  Wilson, 

Secretary. 

Washington,  D.  C,  December  31, 1897. 


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